Salt Water Gargle for COVID: Benefits and Risks

Gargling with salt water has long been a home remedy for sore throats and respiratory discomfort. With the spread of COVID-19, some have turned to this practice in hopes of alleviating symptoms or preventing infection. While it may offer certain benefits, its effectiveness against SARS-CoV-2 remains uncertain.

Understanding how salt water interacts with the throat and how it compares to other gargling solutions can help determine its role in managing symptoms.

Role Of Salt In Household Gargle Solutions

Salt has been used in gargling solutions for centuries due to its osmotic properties and ability to affect the throat’s microenvironment. When dissolved in water, sodium chloride creates a hypertonic solution, meaning it has a higher solute concentration than throat fluids. This draws water out of swollen mucosal cells through osmosis, potentially reducing inflammation and discomfort. The same effect can thin mucus, making it easier to expel irritants and pathogens.

Salt may also help disrupt microbial activity. Hypertonic environments can inhibit bacterial growth by dehydrating microbial cells and interfering with their function. While this effect is more pronounced in bacteria than viruses, some research suggests that salt water may help reduce viral load in the throat by flushing out viral particles. A 2020 study in The Journal of Infectious Diseases found that gargling with saline solutions reduced the presence of certain respiratory viruses in the upper airway, though its impact on SARS-CoV-2 remains unclear.

The mechanical action of gargling also contributes to its benefits. Swishing and expelling liquid helps remove debris, dead cells, and excess mucus, which can otherwise harbor pathogens. However, the effectiveness of salt water gargles depends on concentration, frequency, and duration of use.

Common Ingredients In Gargle Mixtures

Gargle solutions often include additional ingredients that enhance salt’s effects or provide therapeutic benefits. These can range from mild antiseptics to buffering agents that maintain an optimal pH balance.

Baking soda (sodium bicarbonate) is a common addition that acts as a pH adjuster and mild antimicrobial agent. It creates a slightly alkaline environment, which may help neutralize acidity in the throat and interfere with certain pathogens. A 2019 study in BMC Infectious Diseases found that bicarbonate solutions reduced bacterial adhesion in the upper respiratory tract, potentially lowering infection risk.

Antiseptics such as povidone-iodine are also used, particularly in clinical settings. Povidone-iodine has broad-spectrum antimicrobial activity against bacteria, fungi, and some viruses. A 2021 clinical trial in JAMA Otolaryngology found that povidone-iodine gargles temporarily reduced detectable viral RNA in COVID-19 patients but noted that frequent use could cause mucosal irritation, emphasizing the need for proper dilution.

Some gargle solutions include herbal extracts like licorice root or chamomile, known for their soothing and anti-inflammatory properties. Licorice root contains glycyrrhizin, which has documented antiviral effects, while chamomile is rich in flavonoids that may help reduce throat discomfort. A 2018 review in Phytotherapy Research found licorice-based gargles effective in relieving post-operative throat pain.

Variation In Salt Concentrations

The effectiveness of salt water gargles depends on sodium chloride concentration. A mild saline solution, typically around 0.9%, matches the salinity of body fluids and is gentle on the throat. This isotonic concentration is commonly used in medical settings for nasal and throat irrigation.

Higher concentrations, ranging from 2% to 5%, create a hypertonic environment that more aggressively reduces swelling by drawing fluid out of inflamed tissues. However, excessive salt concentrations (above 5%) can dehydrate throat tissues, leading to discomfort or irritation. A 2021 study in Oral Health & Preventive Dentistry found that prolonged use of highly concentrated salt solutions could disrupt the balance of the oropharyngeal microbiome, potentially leading to bacterial overgrowth.

The frequency and duration of gargling also matter. A 2019 review in International Journal of Pediatric Otorhinolaryngology found that gargling with a 2–3% saline solution two to three times per day was generally well-tolerated and provided relief. However, more frequent use, especially with higher concentrations, increased the likelihood of irritation.

Potential Interactions With The Throat

Salt water interacts with the throat by temporarily altering moisture balance and the cellular environment. Saline solutions can help reduce swelling by drawing excess fluid from inflamed tissues, providing a soothing effect. However, prolonged exposure to hypertonic solutions can excessively dehydrate mucosal tissues, potentially worsening irritation.

The throat’s epithelial layer acts as a protective barrier against pathogens and irritants. While mild saline solutions generally support mucosal health, repeated use of high-salt concentrations may strip away the protective mucus layer, making the throat more susceptible to minor abrasions or discomfort. This is particularly relevant for individuals with conditions like laryngitis or chronic pharyngitis, where maintaining adequate moisture is essential for healing.

Comparisons With Non-Salt Gargles

While salt water gargles are widely used for throat discomfort, other solutions may offer additional benefits. These alternatives contain active ingredients that soothe irritation, reduce microbial presence, or promote healing.

Antiseptic gargles, such as those containing chlorhexidine or cetylpyridinium chloride, target bacterial and viral particles by disrupting cell membranes. A 2021 study in The Journal of Hospital Infection found that chlorhexidine gargles significantly reduced SARS-CoV-2 viral load in saliva, though prolonged use may cause taste disturbances or disrupt the oral microbiome.

Herbal and medicated gargles, including those with honey, licorice extract, or povidone-iodine, provide additional soothing effects. Povidone-iodine has antiviral properties, with research in JAMA Otolaryngology suggesting it temporarily reduces SARS-CoV-2 presence in the throat. However, concerns about thyroid interference and mucosal irritation limit its widespread use. Honey-based gargles, while lacking direct antiviral properties, have been shown to relieve symptoms by coating the throat and reducing coughing frequency.

Each of these alternatives presents unique benefits and limitations. The choice of gargling solution depends on individual needs, tolerability, and the symptoms being addressed.